Correct or not meter constant of integral type measuring instrument, directly affect the product can be approval or put into use. This paper takes the mass production of electric energy meter as the research object, the existing hardware and software configuration used in products, electric energy meter constant self checking function table is added on the product. The instrument constant test is to verify the electric energy meter, the internal configuration of the constant value,the output pulse driven testing correctness factor and the electronic meter carry driving factors. Electric energy meter gauge constant self checking function, digital LCD screen is switched to the electric energy accumulation continuous display and instrument output (optical or electrical) pulse synchronization pulse accumulation counting display, and used as the display parameters self operation before the show, self display andself-test results. The cover of electric energy meter function button on the local or infrared remote control button, the electric energy meter products instrument constant self checking function switching, parameters setting, program start and stop. With the instrument constant self-test function of the electric energy meter, constant testing has the advantages of simple operation, less test time and no test error, improve the constant test the reliability of the results.